fix(dashboard): scope decided_at sort to resolved/superseded only

Previous fix applied the decided_at branch to all status groups,
causing open decisions without decided_at (e.g. COULOMBCORE decision)
to sort last behind any open decision that had decided_at set.

Now: decided_at desc only for resolved/superseded; open/escalated
use deadline asc → created_at desc.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

dashboard/src/decisions.md

@@ -31,7 +31,7 @@ const decState = (async function*() {
             const dr = (rank[a.status] ?? 9) - (rank[b.status] ?? 9);
             if (dr !== 0) return dr;
             // Resolved / superseded: most recently decided first
-            if (a.decided_at || b.decided_at) {
+            if (a.status === "resolved" || a.status === "superseded") {
               if (a.decided_at && b.decided_at) return b.decided_at.localeCompare(a.decided_at);
               return a.decided_at ? -1 : 1;
             }